Marking tool



Nov. 26, 1963 F. KREMBEL, JR 3,111,997

- MARKING TOOL Filed Jan. 15, 1962 FRANK KR EM BEL JR.

. H5 Mronngvs United States Patent 3,111,997 MARKING TOOL Frank Krembel, Jr., Detroit, Mich., assignor to Columbia Marking Tools, Inc, Detroit, Mich, a corporation of Michigan Filed Jan. 15, 1962, Ser. No. 166,102 12 Claims. (Cl. 17315) This invention relates to a fluid actuated impact marking tool and, more particularly, to a single blow air hammer capable of delivering a powerful impact blow.

The invention is characterized by the manner in which the impact marking tool or hammer is actuated when a force is applied to the valve ram which carries, as an example, a stamp insert so as to shift the valve ram and vent the chamber immediately adjacent the valve ram to atmosphere. As a result the pressure of fluid acting above the force transmitting member moves the member in a direction to strike the valve ram. The invention is particularly adaptable for taking the place of hand stamps, marking machines, and automatic center punches, and provides an accurately controlled single blow hammer which is ideal for inspection marking, job station identification, and staking, up-setting, light riveting, pindriving and small assembly operations.

The impact marking tool is adapted to carry a low cost marking inseit which is able upon actuation of the tool, to indent up to A characters in tool steel. The invention is further characterized by its compactness, light weight construction, and in addition, provides portability and space economy.

It is an object of the present invention to provide a fluid actuated impact marking tool comprising a housing having a chamber therein, a force transmitting member in said chamber, a valve ram carried by the housing for limited movement between a normally closed position and an opened position, said valve ram being adapted to carry a stamp insert or the like and having one end opposite the force transmitting member, means connecting opposite sides of the force transmitting member to a source of fluid under pressure, and means for venting the side of the force transmitting member opposite said one end of the valve ram to atmosphere upon movement of thte valve ram to an opened position to cause the force transmitting member to strike the valve ram.

Another object of the present invention is to provide an impact marking tool of the aforementioned type wherein resilient means, such as a spring, is provided in the chamber for returning the force transmitting member to its original position upon closing of said valve ram.

Still another object of the present invention is to provide an impact marking tool of the aforementioned type wherein the housing of the marked tool may be provided with a handle which is gripped by the operator or may be provided with means, such as an eyebolt, whereby the marking tool may be connected to a punch press or the like.

A further object of the present invention is to provide an impact marking tool of the aforementioned type wherein a tubular cylinder is provided in the chamber spaced from the walls of the chamber to define a fluid cavity, a restricted bleed passage in the cylinder between the cavity and the interior of the cylinder, a plunger movable in the cylinder, a valve ram carried by the housing for limited movement and having one end opposite one end of the plunger, said valve ram and said plunger being longitudinally aligned, said valve ram having a normally closed position and an opened position, means connecting the cavity and the other end of the plunger to a source of fluid under pressure, said restricted passage in said sleeve transmitting the fluid of pressure from the cavity to the interior of the cylinder, and means for ice venting the cylinder to atmosphere upon the shifting of said valve ram to an opened position to cause the fluid of pressure acting on said other end of the plunger to move said plunger in a direction to strike said valve ram.

A still further object of the present invention is to provide an impact marking tool of the aforementioned type which is connected to a source of air under pressure.

Another object of the present invention is to provide an impact marking tool of the aforementioned type wherein a tubular collar is threaded to one end of the housing, said collar having a valve seat therein and carrying the valve ram for limited movement with respect thereto to control the venting of fluid from the cylinder to the atmosphere.

Still another object of the present invention is to provide an impact marking tool of the aforementioned type wherein a spacer having passage means therein is provided between the sleeve and the collar, said collar holding the sleeve and the spacer in a longitudinally aligned position in the housing.

A further object of the present invention is to provide an air impact marking tool of the aforementioned type wherein suitable sealing means such as O-rings are provided between the collar and the tubular housing, and in addition, around the valve ram for controlling the flow across the valve seat provided in the collar.

It is thus another object of this invention to provide a portable, light weight, simplified, low cost structure of the aforementioned type having certain advantages contributing to efl'iciency, reliability and long life as well as case of maintenance.

FIG. 1 is an elevation of the present invention.

PEG. 2 is a vertical sectional view of the present invention illustrating the valve ram in an opened position.

FIG. 3 is a partial elevational view, partly in section, illustrating the valve ram in a closed position.

FIG. 4 is a sectional View taken on the line 4-4 of FIG. 2.

FIG. 5 is a sectional view taken on the line 55 of FIG. 2.

FIG. 6 is an end view looking in the direction of the arrows 66 of FIG. 1.

FIG. 7 is a sectional view taken on the line 7-7 of FIG. 1.

Referring now to the drawing, the impact marking tool is designated by the numeral 10. The marking tool 10 comprises a housing 12 having a chamber 14 therein. The housing 12 and the chamber 14 are of substantially cylindrical cross-section as illustrated in the drawing.

The chamber 14 is closed at end 16 and opened at end 18. The inner periphery of end 18 is threaded as is indicated at 20 for a purpose to be hereinafter described. The housing 12 is provided with a tubular handle 22 so as to permit the operator to utilize the impact marking tool when gripping the handle 22 thereof. However, it should be understood that the marking tool 10 may be utilized wtihout the handle 22 such as by utilizing an eyebolt, not shown, which is threaded to the threaded opening 24 provided in the closed end 16 of the housing 12 or in threaded opening 25 provided intermediate the ends of the housing 12. The eyebolt in turn is connected, as an example, to a punch press or the like.

A tubular sleeve 26 is received in the chamber 14. The outside cylindrical wall of the sleeve 26 defines a fluid pocket 28 .with the side walls of the chamber 14. The sleeve 26 has one end 30 abutting the shoulder 32 provided at the closed end 16 of the housing 12. A recess or pocket 34 is provided in the closed end 16 for a purpose to be hereinafter described. Circumferentially spaced grooves 36 are provided in the end 30 of the sleeve 26. In FIGURE 5, four such grooves 36 are illustrated.

However, it should be understood that any number of grooves 36 may be utilized.

The chamber 14 is reduced in diameter as indicated at 38 and has a diameter substantially equal to the outside diameter of the sleeve 26. A spacer 40 of cylindrical configuration having a flange 42 and a reduced portion 44 is arranged in the reduced portion 38 of the chamber 14 so that the reduced portion 44 of the spacer 40 is received in the interior of the other end 46 of the sleeve 26 as illustrated in FIGURES 2 and 3. The spacer 40 is provided with a cylindrical opening 48 and a plurality of radially spaced, circumferentially extending passages 50 as best illustrated in FIG. 4.

The sleeve 26 and spacer 40 are held in a longitudinally aligned relationship by means of the threaded collar 56 which is provided with external threads 58 which are adapted to mate with the internal threads 20 on end 18 of the housing 12. The inner end 60 of the collar 56 forms an annular abutment which is adapted to engage the flange 42 of the spacer 40 to hold the spacer 40 and sleeve 26 in the aforementioned assembled position in the housing 12.

The collar 56 is provided with an annular valve seat 64 which extends radially inwardly towards the longitudinal axis of the collar 56 and is located between chambers 66 and 68 in the collar 56. A plurality of radially extending, circumferentially spaced passages 70 are provided in the outer end of the collar 56 to connect chamber 68 to the atmosphere. The collar 56 is provided with a valve passage 72 which is longitudinally aligned with chambers 66 and 68 and valve seat 64. Mounted for limited movement in the collar 56 is a valve ram 76. The valve ram 76 serves a dual purpose as will subsequently appear. The valve ram 76 is provided on the outer end thereof with a tubular cavity 78 which is adapted to receive a marking stamp or insert 80 having characters thereon. The insert 80 is carried by the valve ram 76 by means of a set screw 82.

The other end of the valve ram 76 is provided with a stem 84, a land 86, and an annular valve portion 88 which is adapted to control flow across the valve seat 64. An O-ring 90 is carried by the valve portion 88 and is adapted to engage the valve seat 64 when the valve ram 76 is in a closed position as illustrated in FIG. 3. Another O-ring 89 is provided between the collar 56 and the housing 12 while O-ring 91 is provided around the stem 84 as illustrated.

Restricted passages 92 are provided in the sleeve 26 at circumferentially spaced points. A cylindrically shaped plunger or force transmitting member 94 having a reduced portion 96 opposite the stem 84 of the valve ram 76 is adapted to move in the sleeve 26 to strike the valve ram 76 when the tool or hammer is actuated. A return spring 98 is provided between the spacer 40 and the plunger 94 for returning the plunger 94 to the non-operating position as illustrated by the dotted lines in FIG. 1.

The impact marking tool 10 is adapted to be connected to a suitable source of actuating fluid such as air under pressure through means of an appropriate hose, not shown. The source of air may be connected in one of two different places. If the tubular handle 22 is provided for the housing 12 the source of air is connected to the threaded pipe tap 100. The pipe tap 100 communicates with the cavity 28 through the passage 101 in the handle 22. In the event a punch press or other suitable operating equipment is utilized, the source of pressure is connected to the threaded pipe tap 102 provided in the closed end 16 of the housing 12. Tap 102 is connected to cavity 28 through the grooves 36 provided in sleeve 26.

When it is desired to mark a certain item all that is required is that the ram valve 76 be moved to an opened position with respect to the housing 12 as illustrated in FIGURE 2. This is accomplished by bringing the stamp insert 80 into contact with the work whereby a force applied to the insert 80 will move the valve ram 76 with '4 respect to the housing 12 thereby directing the plunger 94 in its impact stroke.

In operation, fluid under pressure, such as air, whether connected to the pipe tap 102 or pipe tap 100, is delivered to the fluid pocket 28 and to the expansible pocket 34 adjacent the closed end 16 of the housing 12. The fluid of pressure in the fluid pocket 28 is bled through the re stricted passages 92 into the interior 104 of the sleeve 26. Prior to the shifting of the valve ram 76, the fluid of pressure in the pocket 34 and in the interior 104 of sleeve 26 is exposed to equal areas on the plunger 94. As a result the spring 98 holds the valve plunger 94 against the closed end 16 of the housing 12 as illustrated by the dotted lines in FIG. 2.

When it is desired to mark an item, the insert is brought against the Work and the valve ram 76 is moved with respect to the housing 12. As a result, the fluid of pressure in the interior 104 of sleeve 26 is vented to the atmosphere through the passages 50 provided in the spacer 40, through the chamber 66 in the collar 56, across the valve seat 64 around the valve portion 88, through the chamber 68 and through passages 70. Since chamber 104 is vented to atmosphere, immediately an unbalance of forces is created on the plunger 94. As a result the pressure of fluid acting in the expansible pocket 34 on the adjacent end of plunger 94 moves the plunger 94 towards the valve ram 76 so that the reduced portion 96 of the plunger 94 strikes the stem 84 of the valve ram 76 to direct the impact or force to the mark insert 80. By this action the characters of the insert 80 are impressed on the item to be marked.

Upon the striking of the ram valve 76 by the plunger 94, the ram valve 76 is returned to the closed position as illustrated in FIG. 3. As a result, the spring 98 assisted by the pressure of the fluid beneath the plunger 94 returns the plunger 94 to the position adjacent the closed end 16 of the housing 12.

The collar 56 is provided with flats 106 so that a wrench or other similar tool may be placed thereon to insert the collar 56 in or remove the collar 56 from the housing 12.

The present invention is adapted for trouble free operation since only two moving parts are utilized. The housing 12 is preferably made from a lightweight metal such as aluminum while the sleeve collar, plunger, valve ram and spacer are preferably made from a metal such as steel.

The drawings and the foregoing specification constitute a description of the improved marking tool in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

1. A single blow fluid operated hammer comprising a housing, a chamber in said housing, a force transmitting member in said chamber, a valve ram carried by said housing for limited movement between a normally closed position and an opened position, said valve ram being adapted to carry a tool and having one end opposite said force transmitting member, means connecting opposite sides of said force transmitting member to a source of fluid under pressure, and means operable upon movement of said valve ram to said opened position for venting the side of said force transmitting member opposite said one end of the valve ram to atmosphere to cause said force transmitting member to strike said valve ram due to the pressure of fluid acting on the other side of said force transmitting member.

2. A single blow fluid operated hammer comprising a housing, a chamber in said housing, a force transmitting member in said chamber, a valve ram carried by said housing for limited movement between a normally closed position and an opened position, said valve ram being adapted to carry a tool and having one end opposite said force transmitting member, means connecting opposite sides of said force transmitting member to a source of fluid under pressure, means operable upon movement of said valve ram to said opened position for venting the side of said force transmitting member opposite said one end of the valve ram to atmosphere to cause said force transmitting member to strike said valve ram due to the pressure of fluid acting on the other side of said force trans mitting member, and resilient means in said chamber for returning said cforce transmitting member to its original position upon closing of said valve ram.

3. A single blow fluid operated hammer comprising a housing, a chamber in said housing, a tubular sleeve in said chamber spaced from the walls of said chamber to define a fluid cavity, a restricted bleed passage in said sleeve between said cavity and the interior of said sleeve, a plunger movable in said sleeve, a valve ram carried by said housing for limited movement, said valve ram being in longitudinal alignment with said plunger and having an end opposite one end of said plunger, said valve ram having a normally closed position and an opened position, means connecting said cavity and the other end of said plunger to a source of fluid under pressure, said restricted passage transmitting the fluid of pressure from the cavity to the interior of the sleeve, and means for venting said sleeve to atmosphere upon the shifting of said valve ram to an opened position to cause the pressure acting on said plunger to move said plunger in a direction to strike said valve ram.

4. A single blow fluid operated hammer comprising a housing, a chamber in said housing, a tubular sleeve in said chamber spaced from the walls of said chamber to define a fluid cavity, a restricted bleed passage in said sleeve between said cavity and the interior of said sleeve, a plunger movable in said sleeve, a valve ram carried by said housing for limited movement, said valve ram being in longitudinal alignment with said plunger and having an end opposite one end of said plunger, said valve ram having a normally closed position and an opened position, means connecting said cavity and the other end of said plunger to a source of fluid under pressure, said restricted passage transmitting the fluid of pressure from the cavity to the interior of the sleeve, and means for venting said sleeve to atmosphere upon the shifting of said valve ram to an opened position to cause the pressure acting on said plunger to move said plunger in a direction to strike said valve ram, and resilient means in said chamber for returning said plunger to its original position upon closing of said valve ram.

5. A single blow fluid operated hammer defined in claim 4 wherein said resilient means is a spring.

6. A single blow fluid operated hammer comprising a housing, a chamber in said housing which is opened at one end thereof, a tubular sleeve in said chamber spaced from the walls of said chamber to define a fluid cavity, a restricted bleed passage in said sleeve between said cavity and the interior of said sleeve, a plunger movable in said sleeve, a tubular collar threaded to the open end of said housing for closing same, a valve seat in said collar, a valve ram carried by said collar for limited movement for controlling the flow or" fluid across the valve seat, said valve ram being in longitudinal alignment with said plunger and having one end opposite one end of said plunger, said valve ram having a normally closed position and an opened position with respect to said valve seat, means connecting said cavity and the other end of said plunger to a source of fluid under pressure, said restricted passage transmitting the fluid of pressure from the cavity to the interior of the sleeve, and means for venting said sleeve to the atmosphere across said valve seat upon the shifting of said valve ram to an opened position to cause the pressure of fluid acting on said other end of the plunger to move said plunger in a direction to strike said valve ram.

7. A single blow fluid operated hammer defined in claim 6 wherein a spacer is provided in said chamber between said sleeve and said collar, said spacer being provided with a plurality of passages which connect the interior of said sleeve with the upstream side of said valve seat.

8. A single blow fluid operated hammer defined in claim 6 wherein sealing means is provided between the collar and the housing for preventing leakage of fluid therebetween.

9. A single blow fluid operated hammer defined in claim 6 wherein an O-ring seal is carried by the valve ram which engages the valve seat when the valve ram is in a closed position to prevent the leakage of fluid across the valve seat.

10. A single 'blow fluid operated hammer defined in claim 6 wherein grooves are provided in said sleeve for connecting said cavity to said other end of said plunger.

11. A single *blow fluid operated hammer defined in claim 6 wherein resilient means are provided in said chamber for biasing said plunger in a direction away from said valve ram.

12. A single blow fluid operated hammer defined in claim 11 wherein said resilient means is a spring.

References Cited in the file of this patent UNITED STATES PATENTS 2,100,092 Tear Nov. 23, 1937 2,513,271 Bluemink et al. July 4, 1950 2,854,953 Osborne Oct. 7, 1958 2,899,935 Dalton Aug. 18, 1959 2,905,149 Swanson Sept. 22, 1959 2,938,534 Bos May 31, 1960 2,944,521 ICibbe July 12, 1960 2,955,573 Feucht Oct. 11, 1960 2,989,750 MoIlvin June 27, 1961 

1. A SINGLE BLOW FLUID OPERATED HAMMER COMPRISING A HOUSING, A CHAMBER IN SAID HOUSING, A FORCE TRANSMITTING MEMBER IN SAID CHAMBER, A VALVE RAM CARRIED BY SAID HOUSING FOR LIMITED MOVEMENT BETWEEN A NORMALLY CLOSED POSITION AND AN OPENED POSITION, SAID VALVE RAM BEING ADAPTED TO CARRY A TOOL AND HAVING ONE END OPPOSITE SAID FORCE TRANSMITTING MEMBER, MEANS CONNECTING OPPOSITE SIDES OF SAID FORCE TRANSMITTING MEMBER TO A SOURCE OF FLUID UNDER PRESSURE, AND MEANS OPERABLE UPON MOVEMENT OF SAID VALVE RAM TO SAID OPENED POSITION FOR VENTING THE SIDE OF SAID FORCE TRANSMITTING MEMBER OPPOSITE SAID ONE END OF THE VALVE RAM TO ATMOSPHERE TO CAUSE SAID FORCE TRANSMITTING MEMBER TO STRIKE SAID VALVE RAM DUE TO THE PRESSURE OF FLUID ACTING ON THE OTHER SIDE OF SAID FORCE TRANSMITTING MEMBER. 